People today can readily communicate with one another in many different ways. Telephones, cell phones, electronic mail, instant messaging, video conferencing, and application sharing are just some examples to name a few. Despite the many avenues of communication, however, it can be difficult and frustrating effectively to reach someone. For instance, when a caller seeks to speak with someone in particular, that person might be in a meeting or traveling or currently on the telephone. Presently, the caller has little inkling of whether there will be success before making the call. Moreover, information regarding the availability and reachability of the person is generally unavailable, spread about in various places, or requires custom client software to access.
For example, if a caller desires to know if a person is available by telephone, the caller typically needs to call the person, and then often learns that the person is unavailable only upon receiving a busy signal or being directed to voicemail. To know if a person is online (i.e., connected to a computer), the caller may need to launch one or multiple IM (Instant Messaging) client, such as Yahoo!™ or MSN™ client software, provided that the userID of the called person is known and that the called person has pre-authorized the caller. Even if the called person is online, however, it does not ensure that the person is actually at his computer. The caller might then need to send an instant message and wait for a response. As for determining whether a person is in a meeting, a caller can access a number of online calendars (often available within enterprises), but if the caller is external to the enterprise, the online calendar may be inaccessible.
Consequently, to reach a particular person, a caller may need to call various telephone numbers (landline, mobile, and SIP (session initiation protocol) addresses), send email messages in order to coordinate a time when both caller and called are available, access and look up calendar information, launch client software for obtaining presence information, and manually gather availability information from IM (instant messaging) clients. The process is unpredictable, impractical, and often unfruitful.